From e7239148d6dab4482e0f97958c077102295c31c7 Mon Sep 17 00:00:00 2001 From: Jakub Wartak Date: Fri, 21 Feb 2025 11:17:28 +0100 Subject: [PATCH v3 2/3] Extend pg_buffercache with new view pg_buffercache_numa to show NUMA zone --- contrib/pg_buffercache/Makefile | 3 +- contrib/pg_buffercache/meson.build | 1 + .../pg_buffercache--1.5--1.6.sql | 30 +++++ contrib/pg_buffercache/pg_buffercache.control | 2 +- contrib/pg_buffercache/pg_buffercache_pages.c | 113 +++++++++++++++++- src/backend/utils/misc/guc_tables.c | 2 +- src/include/storage/pg_shmem.h | 1 + 7 files changed, 146 insertions(+), 6 deletions(-) create mode 100644 contrib/pg_buffercache/pg_buffercache--1.5--1.6.sql diff --git a/contrib/pg_buffercache/Makefile b/contrib/pg_buffercache/Makefile index eae65ead9e5..2a33602537e 100644 --- a/contrib/pg_buffercache/Makefile +++ b/contrib/pg_buffercache/Makefile @@ -8,7 +8,8 @@ OBJS = \ EXTENSION = pg_buffercache DATA = pg_buffercache--1.2.sql pg_buffercache--1.2--1.3.sql \ pg_buffercache--1.1--1.2.sql pg_buffercache--1.0--1.1.sql \ - pg_buffercache--1.3--1.4.sql pg_buffercache--1.4--1.5.sql + pg_buffercache--1.3--1.4.sql pg_buffercache--1.4--1.5.sql \ + pg_buffercache--1.5--1.6.sql PGFILEDESC = "pg_buffercache - monitoring of shared buffer cache in real-time" REGRESS = pg_buffercache diff --git a/contrib/pg_buffercache/meson.build b/contrib/pg_buffercache/meson.build index 12d1fe48717..9b2e9393410 100644 --- a/contrib/pg_buffercache/meson.build +++ b/contrib/pg_buffercache/meson.build @@ -23,6 +23,7 @@ install_data( 'pg_buffercache--1.2.sql', 'pg_buffercache--1.3--1.4.sql', 'pg_buffercache--1.4--1.5.sql', + 'pg_buffercache--1.5--1.6.sql', 'pg_buffercache.control', kwargs: contrib_data_args, ) diff --git a/contrib/pg_buffercache/pg_buffercache--1.5--1.6.sql b/contrib/pg_buffercache/pg_buffercache--1.5--1.6.sql new file mode 100644 index 00000000000..e5b3d1f7dd2 --- /dev/null +++ b/contrib/pg_buffercache/pg_buffercache--1.5--1.6.sql @@ -0,0 +1,30 @@ +/* contrib/pg_buffercache/pg_buffercache--1.5--1.6.sql */ + +-- complain if script is sourced in psql, rather than via CREATE EXTENSION +\echo Use "CREATE EXTENSION pg_buffercache" to load this file. \quit + +-- Register the function. +DROP FUNCTION pg_buffercache_pages() CASCADE; + +CREATE OR REPLACE FUNCTION pg_buffercache_pages(boolean) +RETURNS SETOF RECORD +AS 'MODULE_PATHNAME', 'pg_buffercache_pages' +LANGUAGE C PARALLEL SAFE; + +-- Create a view for convenient access. +CREATE OR REPLACE VIEW pg_buffercache AS + SELECT P.* FROM pg_buffercache_pages(false) AS P + (bufferid integer, relfilenode oid, reltablespace oid, reldatabase oid, + relforknumber int2, relblocknumber int8, isdirty bool, usagecount int2, + pinning_backends int4); + +CREATE OR REPLACE VIEW pg_buffercache_numa AS + SELECT P.* FROM pg_buffercache_pages(true) AS P + (bufferid integer, relfilenode oid, reltablespace oid, reldatabase oid, + relforknumber int2, relblocknumber int8, isdirty bool, usagecount int2, + pinning_backends int4, numa_zone_id int4); + +-- Don't want these to be available to public. +REVOKE ALL ON FUNCTION pg_buffercache_pages(boolean) FROM PUBLIC; +REVOKE ALL ON pg_buffercache FROM PUBLIC; +REVOKE ALL ON pg_buffercache_numa FROM PUBLIC; diff --git a/contrib/pg_buffercache/pg_buffercache.control b/contrib/pg_buffercache/pg_buffercache.control index 5ee875f77dd..b030ba3a6fa 100644 --- a/contrib/pg_buffercache/pg_buffercache.control +++ b/contrib/pg_buffercache/pg_buffercache.control @@ -1,5 +1,5 @@ # pg_buffercache extension comment = 'examine the shared buffer cache' -default_version = '1.5' +default_version = '1.6' module_pathname = '$libdir/pg_buffercache' relocatable = true diff --git a/contrib/pg_buffercache/pg_buffercache_pages.c b/contrib/pg_buffercache/pg_buffercache_pages.c index 3ae0a018e10..a5aab07fc99 100644 --- a/contrib/pg_buffercache/pg_buffercache_pages.c +++ b/contrib/pg_buffercache/pg_buffercache_pages.c @@ -6,6 +6,7 @@ * contrib/pg_buffercache/pg_buffercache_pages.c *------------------------------------------------------------------------- */ +#include "pg_config.h" #include "postgres.h" #include "access/htup_details.h" @@ -13,10 +14,16 @@ #include "funcapi.h" #include "storage/buf_internals.h" #include "storage/bufmgr.h" +#ifdef USE_LIBNUMA +#include +#include +#include +#endif +#include "storage/pg_shmem.h" #define NUM_BUFFERCACHE_PAGES_MIN_ELEM 8 -#define NUM_BUFFERCACHE_PAGES_ELEM 9 +#define NUM_BUFFERCACHE_PAGES_ELEM 10 #define NUM_BUFFERCACHE_SUMMARY_ELEM 5 #define NUM_BUFFERCACHE_USAGE_COUNTS_ELEM 4 @@ -43,6 +50,7 @@ typedef struct * because of bufmgr.c's PrivateRefCount infrastructure. */ int32 pinning_backends; + int32 numa_zone_id; } BufferCachePagesRec; @@ -65,6 +73,15 @@ PG_FUNCTION_INFO_V1(pg_buffercache_summary); PG_FUNCTION_INFO_V1(pg_buffercache_usage_counts); PG_FUNCTION_INFO_V1(pg_buffercache_evict); +static void +pg_buffercache_mark_numa_invalid(BufferCachePagesContext *fctx, int n) +{ + int i; + for (i = 0; i < n; i++) { + fctx->record[i].numa_zone_id = -1; + } +} + Datum pg_buffercache_pages(PG_FUNCTION_ARGS) { @@ -75,10 +92,16 @@ pg_buffercache_pages(PG_FUNCTION_ARGS) TupleDesc tupledesc; TupleDesc expected_tupledesc; HeapTuple tuple; + Buffer query_numa = PG_GETARG_BOOL(0); if (SRF_IS_FIRSTCALL()) { - int i; + int i, blk2page, j; + Size os_page_size; + void **os_page_ptrs; + int *os_pages_status; + int os_page_count; + float pages_per_blk; funcctx = SRF_FIRSTCALL_INIT(); @@ -122,10 +145,14 @@ pg_buffercache_pages(PG_FUNCTION_ARGS) TupleDescInitEntry(tupledesc, (AttrNumber) 8, "usage_count", INT2OID, -1, 0); - if (expected_tupledesc->natts == NUM_BUFFERCACHE_PAGES_ELEM) + if (expected_tupledesc->natts >= NUM_BUFFERCACHE_PAGES_ELEM-1) TupleDescInitEntry(tupledesc, (AttrNumber) 9, "pinning_backends", INT4OID, -1, 0); + if (expected_tupledesc->natts == NUM_BUFFERCACHE_PAGES_ELEM) + TupleDescInitEntry(tupledesc, (AttrNumber) 10, "numa_zone_id", + INT4OID, -1, 0); + fctx->tupdesc = BlessTupleDesc(tupledesc); /* Allocate NBuffers worth of BufferCachePagesRec records. */ @@ -140,6 +167,30 @@ pg_buffercache_pages(PG_FUNCTION_ARGS) /* Return to original context when allocating transient memory */ MemoryContextSwitchTo(oldcontext); + /* This is for gathering some NUMA statistics. We might be using + * various DB block sizes (4kB, 8kB , .. 32kB) that end up being + * allocated in various different OS memory pages sizes, so first + * we need to understand the OS memory page size before + * calling move_pages() + */ + os_page_size = sysconf(_SC_PAGESIZE); + if(huge_pages_status == HUGE_PAGES_ON) + GetHugePageSize(&os_page_size, NULL); + os_page_count = (NBuffers * BLCKSZ) / os_page_size; + pages_per_blk = (float) BLCKSZ / os_page_size; + + elog(NOTICE, "os_page_count=%d os_page_size=%ld pages_per_blk=%f", + os_page_count, os_page_size, pages_per_blk); + + os_page_ptrs = palloc(sizeof(void *) * os_page_count); + os_pages_status = palloc(sizeof(int) * os_page_count); + memset(os_page_ptrs, 0, sizeof(void *) * os_page_count); + /* + * If we get ever 0xff back from kernel inquiry, then we probably + * have bug in our buffers to OS page mapping code here + */ + memset(os_pages_status, 0xff, sizeof(int) * os_page_count); + /* * Scan through all the buffers, saving the relevant fields in the * fctx->record structure. @@ -177,8 +228,61 @@ pg_buffercache_pages(PG_FUNCTION_ARGS) else fctx->record[i].isvalid = false; +#ifdef USE_LIBNUMA +/* FIXME: taken from bufmgr.c, maybe move to .h ? */ +#define BufHdrGetBlock(bufHdr) ((Block) (BufferBlocks + ((Size) (bufHdr)->buf_id) * BLCKSZ)) + blk2page = (int) i * pages_per_blk; + j = 0; + do { + /* + * Many buffers can point to the same page, but we want to + * query just first address. + * + * In order to get reliable results we also need to touch memory pages + * so that inquiry about NUMA zone doesn't return -2. + */ + if(os_page_ptrs[blk2page+j] == 0) { + volatile uint64 touch pg_attribute_unused(); + os_page_ptrs[blk2page+j] = (char *)BufHdrGetBlock(bufHdr) + (os_page_size*j); + touch = *(uint64 *)os_page_ptrs[blk2page+j]; + } + j++; + } while(j < (int)pages_per_blk); +#endif + UnlockBufHdr(bufHdr, buf_state); } + + +#ifdef USE_LIBNUMA + if(query_numa) { + /* According to numa(3) it is required to initialize library even if that's no-op. */ + if(numa_available() == -1) { + pg_buffercache_mark_numa_invalid(fctx, NBuffers); + elog(NOTICE, "libnuma initialization failed, some NUMA data might be unavailable.");; + } else { + /* Amortize the number of pages we need to query about */ + if(numa_move_pages(0, os_page_count, os_page_ptrs, NULL, os_pages_status, 0) == -1) { + elog(ERROR, "failed NUMA pages inquiry status"); + } + for (i = 0; i < NBuffers; i++) { + blk2page = (int) i * pages_per_blk; + /* Technically we can get errors too here and pass that to user + * + * XXX:: also we could somehow report single DB block spanning + * more than 2 NUMA zones, but it should be rare (?) + */ + fctx->record[i].numa_zone_id = os_pages_status[blk2page]; + } + } + } else + pg_buffercache_mark_numa_invalid(fctx, NBuffers); +#else + pg_buffercache_mark_numa_invalid(fctx, NBuffers); +#endif + + pfree(os_page_ptrs); + pfree(os_pages_status); } funcctx = SRF_PERCALL_SETUP(); @@ -211,6 +315,7 @@ pg_buffercache_pages(PG_FUNCTION_ARGS) nulls[7] = true; /* unused for v1.0 callers, but the array is always long enough */ nulls[8] = true; + nulls[9] = true; } else { @@ -231,6 +336,8 @@ pg_buffercache_pages(PG_FUNCTION_ARGS) /* unused for v1.0 callers, but the array is always long enough */ values[8] = Int32GetDatum(fctx->record[i].pinning_backends); nulls[8] = false; + values[9] = Int32GetDatum(fctx->record[i].numa_zone_id); + nulls[9] = false; } /* Build and return the tuple. */ diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c index 03a6dd49154..172309d389a 100644 --- a/src/backend/utils/misc/guc_tables.c +++ b/src/backend/utils/misc/guc_tables.c @@ -562,7 +562,7 @@ static int ssl_renegotiation_limit; */ int huge_pages = HUGE_PAGES_TRY; int huge_page_size; -static int huge_pages_status = HUGE_PAGES_UNKNOWN; +int huge_pages_status = HUGE_PAGES_UNKNOWN; /* * These variables are all dummies that don't do anything, except in some diff --git a/src/include/storage/pg_shmem.h b/src/include/storage/pg_shmem.h index b99ebc9e86f..5f7d4b83a60 100644 --- a/src/include/storage/pg_shmem.h +++ b/src/include/storage/pg_shmem.h @@ -45,6 +45,7 @@ typedef struct PGShmemHeader /* standard header for all Postgres shmem */ extern PGDLLIMPORT int shared_memory_type; extern PGDLLIMPORT int huge_pages; extern PGDLLIMPORT int huge_page_size; +extern PGDLLIMPORT int huge_pages_status; /* Possible values for huge_pages and huge_pages_status */ typedef enum -- 2.39.5